The effect of synthesis media on the properties of substituted polyaniline/chitosan composites

Substituted polyaniline/chitosan (sPANI/Ch) composites were chemically synthesized in H₂SO₄ and CH₃COOH synthesis media. Structural and physical properties of the composites were characterized by using FTIR, SEM, TGA, UV–vis, XRD techniques, and conductivity measurements. The effect of synthesis media on morphology, thermal stability, conductivity, and crystalline properties was investigated. Chemical interactions between substituted polyanilines and chitosan were explained using FTIR spectra results. The different morphological surfaces were observed in SEM images of the composites. The size of the substituted polyaniline/chitosan (sPANI/Ch) composites was in nanoscale, and the composites synthesized in acetic acid media showed smaller structures than those of H₂SO₄ media and pure chitosan. It was interpreted from XRD results that the composites have amorphous structure and the PNEANI/Ch–CH₃COOH composite has the highest crystallinity.     

The Roles of Melatonin and Vitamin E Plus Selenium in Prevention of Oxidative Stress Induced by Naloxone-Precipitated Withdrawal in Heroin-Addicted Rats

The therapeutic effects of melatonin or vitamin E plus Se (vE + Se) on the restrain of the heroin withdrawal-induced oxidative stress were studied. For this, rats were divided into ten groups. The rats were injected by fixed or variable doses of heroin for 16 consecutive days, and naloxone was given 1 h after the last heroin injection. One hour after naloxone administration, some groups were treated with melatonin or vE + Se. After 1 h this, blood samples were taken, and the levels of malondialdehyde (MDA) and reduced glutathione (GSH) in whole blood, ascorbic acid, α-tocopherol, retinol, β-carotene, nitrite, nitrate, and ceruloplasmin levels in the serum were measured. Our findings showed that, naloxone administration precipitated the heroin withdrawal. This also increased the level of MDA and decreased the levels of GSH in blood. Melatonin or vE + Se administration prevented the rise in MDA levels and increased the GSH levels. On the other hand, there were some significant differences between α-tocopherol, retinol, β-carotene, nitrite, nitrate, and ceruloplasmin levels of experimental groups. Results of present study showed that heroin withdrawal increased the lipid peroxidation and depressed endogenous antioxidative systems. Additionally, melatonin or vE + Se administrations prevented lipid peroxidation and augmented endogenous antioxidant defense systems.     

Biodegradation of cefdinir by a novel yeast strain,Ustilago sp. SMN03 isolated from pharmaceutical wastewater

Cefdinir, a semi-synthetic third generation cephalosporin antibiotic being considered as an emerging pollutant, demands removal from aquatic ecosystems. A yeast strain isolated from pharmaceutical wastewater which was identified as Ustilago sp. SMN03 by molecular techniques and was found to be capable of utilizing cefdinir as a sole carbon source. The isolate was found to degrade 81 % of cefdinir within 6 days under optimized conditions viz. pH 6.0, temperature 30 °C, a shaking speed of 120 rpm, an inoculum dosage of 4 % (w/v) and an initial cefdinir concentration of 200 mg L^?1. Kinetic studies revealed that cefdinir degradation followed the pseudo-first order model, a rate constant of 0.222 per day and a half-life period of 3.26 days. Using LC–MS analysis, six novel intermediates formed during the cefdinir degradation were identified and characterized. FT-IR analysis showed that the functional groups ranging from 1,766 to 1,519 cm^?1, characteristic for lactam ring were completely removed during the cefdinir degradation. The opening of the β-lactam ring was one of the major steps in the cefdinir degradation process. Based on the results from the present study, a possible pathway of cefdinir degradation by Ustilago sp. SMN03 was proposed. To the best of our knowledge, this is the first report on microbial degradation of cefdinir by yeast.     

Insecticidal Metabolites from the Rhizomes of Veratrum album against Adults of Colorado Potato Beetle,Leptinotarsa decemlineata

The dried rhizomes of Veratrum album were individually extracted with CHCl₃, acetone, and NH₄OH/benzene to test the toxic effects against the Colorado potato beetle, Leptinotarsa decemlineata, which is an important agricultural pest. Fifteen compounds in various amounts were isolated from the extracts using column and thin‐layer chromatography. The chemical structures of 14 compounds were characterized as octacosan‐1‐ol ( 1 ), β‐sitosterol ( 2 ), stearic acid ( 3 ), diosgenin ( 4 ), resveratrol ( 5 ), wittifuran X ( 6 ), oxyresveratrol ( 7 ), β‐sitosterol 3‐O‐β‐D ‐glucopyranoside ( 8 ), diosgenin 3‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucopyronoside ( 9 ), oxyresveratrol 3‐O‐β‐D ‐glucopyranoside ( 10 ), jervine ( 11 ), pseudojervine ( 13 ), 5,6‐dihydro‐1‐hydroxyjervine ( 14 ), and saccharose ( 15 ) using UV, IR, MS, ¹H‐ and ¹³C‐NMR, and 2D‐NMR spectroscopic methods. However, the chemical structure of 12 , an oligosaccharide, has not fully been elucidated. Compounds 4, 6, 9 , and 10 were isolated from V. album rhizomes for the first time in the current study. The toxic effects of three extracts (acetone, CHCl₃, and NH₄OH/benzene) and six metabolites, 2, 2 + 4, 5, 7, 8 , and 11 , were evaluated against the Colorado potato beetle. The assay revealed that all three extracts, and compounds 7, 8 , and 11 exhibited potent toxic effects against this pest. This is the first report on the evaluation of the toxic effects of the extracts and secondary metabolites of V. album rhizomes against L. decemlineata. Based on these results, it can be concluded that the extracts can be used as natural insecticides.     

Determining the quality and complexity of next-generation sequencing data without a reference genome

We describe an open-source kPAL package that facilitates an alignment-free assessment of the quality and comparability of sequencing datasets by analyzing k-mer frequencies. We show that kPAL can detect technical artefacts such as high duplication rates, library chimeras, contamination and differences in library preparation protocols. kPAL also successfully captures the complexity and diversity of microbiomes and provides a powerful means to study changes in microbial communities. Together, these features make kPAL an attractive and broadly applicable tool to determine the quality and comparability of sequence libraries even in the absence of a reference sequence. kPAL is freely available at https://github.com/LUMC/kPAL.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-014-0555-3) contains supplementary material, which is available to authorized users.     

Fish oil rich in eicosapentaenoic acid protects against oxidative stress-related renal dysfunction induced by TCDD in Wistar rats

Humans are systemically exposed to persistent organic pollutants, of which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has become a major environmental concern. Exposure to TCDD results in a wide variety of adverse health effects which is mediated by oxidative stress through CYP1A1 activation and arachidonic acid metabolites. Eicosapentaenoic acid (EPA) exhibits antioxidant property and competes with arachidonic acid in membrane phospholipids and produces anti-inflammatory EPA derivatives. Since both EPA and its derivatives have been reported to enhance the antioxidant mechanism, the present study aimed at studying whether EPA could offer protection against TCDD-induced oxidative stress and nephrotoxicity in Wistar rats. Estimation of kidney markers (serum urea and creatinine) and histopathological studies revealed that EPA treatment significantly reduced TCDD-induced renal damage. TCDD-induced oxidative damage was reflected in a significant increase in CYP1A1 activity and lipid peroxide levels with a concomitant decline in non-enzymic antioxidant (GSH) and various enzymic antioxidants such catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), and glutathione peroxidase (GPx). In addition, TCDD-induced oxidative stress also resulted in decline in Na⁺-K⁺ and Mg²⁺ATPases activities with increase in Ca²⁺ ATPases activity. Oral treatment with EPA showed a significant cytoprotection against TCDD-induced renal oxidative stress by decreased CYP1A1 activity and enhanced antioxidant status. TCDD-induced alterations in ATPase enzyme activities were also prevented by EPA treatment. Our results show clear evidence that EPA ameliorates TCDD-induced oxidative stress and kidney damage; thus suggest the potential of EPA as an effective therapeutic agent against toxic effects mediated through redox imbalance.     

α-SNAP Interferes with the Zippering of the SNARE Protein Membrane Fusion Machinery

Neuronal exocytosis is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. Before fusion, SNARE proteins form complexes bridging the membrane followed by assembly toward the C-terminal membrane anchors, thus initiating membrane fusion. After fusion, the SNARE complex is disassembled by the AAA-ATPase N-ethylmaleimide-sensitive factor that requires the cofactor α-SNAP to first bind to the assembled SNARE complex. Using chromaffin granules and liposomes we now show that α-SNAP on its own interferes with the zippering of membrane-anchored SNARE complexes midway through the zippering reaction, arresting SNAREs in a partially assembled trans-complex and preventing fusion. Intriguingly, the interference does not result in an inhibitory effect on synaptic vesicles, suggesting that membrane properties also influence the final outcome of α-SNAP interference with SNARE zippering. We suggest that binding of α-SNAP to the SNARE complex affects the ability of the SNARE complex to harness energy or transmit force to the membrane.     

Immunohistochemical and immunocytochemical findings associated with Marek’s disease virus in naturally infected laying hens

We compared immunohistochemical (IHC) staining of tissue sections of liver, kidney, spleen, lung, proventriculus, sciatic nerve, bursa of Fabricius, brain, heart, intestine and skin; immunocytochemical (ICC) staining of peripheral blood samples and touch preparations of liver, spleen and kidney of laying hens naturally infected with Marek’s disease (MD) virus. We used one hundred and fifty 5-17-week-old commercial hens. IHC and ICC staining were performed using polymer-based techniques. IHC staining exhibited mostly free immunopositive reactions in tumor cells and in the cytoplasm of the parenchymal cells of liver, kidney, spleen and bursa of Fabricius. In the sciatic nerve, severe reactions were observed in the cytoplasm of plasma and MD cells in the lymphoproliferative areas. Pronounced staining was found in the lymphoid cells in the medulla of intrafollicular regions in the bursa of Fabricius. Although immunostaining was observed in the liver and spleen touch preparations, there was no staining in the kidneys and peripheral blood cell samples. The presence of virus in the tissue and peripheral blood samples and in touch preparations was compared immunohistochemically and immunocytochemically. IHC and ICC techniques were helpful for diagnosis of MD. Peripheral blood samples are inappropriate for field conditions and natural infections.